1 /* 2 * Copyright (c) 2012-2016 Pablo Neira Ayuso <[email protected]> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/module.h> 11 #include <linux/skbuff.h> 12 #include <linux/netlink.h> 13 #include <linux/netfilter.h> 14 #include <linux/netfilter/nf_tables.h> 15 #include <net/netfilter/nf_tables.h> 16 17 #define nft_objref_priv(expr) *((struct nft_object **)nft_expr_priv(expr)) 18 19 static void nft_objref_eval(const struct nft_expr *expr, 20 struct nft_regs *regs, 21 const struct nft_pktinfo *pkt) 22 { 23 struct nft_object *obj = nft_objref_priv(expr); 24 25 obj->ops->eval(obj, regs, pkt); 26 } 27 28 static int nft_objref_init(const struct nft_ctx *ctx, 29 const struct nft_expr *expr, 30 const struct nlattr * const tb[]) 31 { 32 struct nft_object *obj = nft_objref_priv(expr); 33 u8 genmask = nft_genmask_next(ctx->net); 34 u32 objtype; 35 36 if (!tb[NFTA_OBJREF_IMM_NAME] || 37 !tb[NFTA_OBJREF_IMM_TYPE]) 38 return -EINVAL; 39 40 objtype = ntohl(nla_get_be32(tb[NFTA_OBJREF_IMM_TYPE])); 41 obj = nft_obj_lookup(ctx->net, ctx->table, 42 tb[NFTA_OBJREF_IMM_NAME], objtype, 43 genmask); 44 if (IS_ERR(obj)) 45 return -ENOENT; 46 47 nft_objref_priv(expr) = obj; 48 obj->use++; 49 50 return 0; 51 } 52 53 static int nft_objref_dump(struct sk_buff *skb, const struct nft_expr *expr) 54 { 55 const struct nft_object *obj = nft_objref_priv(expr); 56 57 if (nla_put_string(skb, NFTA_OBJREF_IMM_NAME, obj->key.name) || 58 nla_put_be32(skb, NFTA_OBJREF_IMM_TYPE, 59 htonl(obj->ops->type->type))) 60 goto nla_put_failure; 61 62 return 0; 63 64 nla_put_failure: 65 return -1; 66 } 67 68 static void nft_objref_destroy(const struct nft_ctx *ctx, 69 const struct nft_expr *expr) 70 { 71 struct nft_object *obj = nft_objref_priv(expr); 72 73 obj->use--; 74 } 75 76 static struct nft_expr_type nft_objref_type; 77 static const struct nft_expr_ops nft_objref_ops = { 78 .type = &nft_objref_type, 79 .size = NFT_EXPR_SIZE(sizeof(struct nft_object *)), 80 .eval = nft_objref_eval, 81 .init = nft_objref_init, 82 .destroy = nft_objref_destroy, 83 .dump = nft_objref_dump, 84 }; 85 86 struct nft_objref_map { 87 struct nft_set *set; 88 enum nft_registers sreg:8; 89 struct nft_set_binding binding; 90 }; 91 92 static void nft_objref_map_eval(const struct nft_expr *expr, 93 struct nft_regs *regs, 94 const struct nft_pktinfo *pkt) 95 { 96 struct nft_objref_map *priv = nft_expr_priv(expr); 97 const struct nft_set *set = priv->set; 98 const struct nft_set_ext *ext; 99 struct nft_object *obj; 100 bool found; 101 102 found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg], 103 &ext); 104 if (!found) { 105 regs->verdict.code = NFT_BREAK; 106 return; 107 } 108 obj = *nft_set_ext_obj(ext); 109 obj->ops->eval(obj, regs, pkt); 110 } 111 112 static int nft_objref_map_init(const struct nft_ctx *ctx, 113 const struct nft_expr *expr, 114 const struct nlattr * const tb[]) 115 { 116 struct nft_objref_map *priv = nft_expr_priv(expr); 117 u8 genmask = nft_genmask_next(ctx->net); 118 struct nft_set *set; 119 int err; 120 121 set = nft_set_lookup_global(ctx->net, ctx->table, 122 tb[NFTA_OBJREF_SET_NAME], 123 tb[NFTA_OBJREF_SET_ID], genmask); 124 if (IS_ERR(set)) 125 return PTR_ERR(set); 126 127 if (!(set->flags & NFT_SET_OBJECT)) 128 return -EINVAL; 129 130 priv->sreg = nft_parse_register(tb[NFTA_OBJREF_SET_SREG]); 131 err = nft_validate_register_load(priv->sreg, set->klen); 132 if (err < 0) 133 return err; 134 135 priv->binding.flags = set->flags & NFT_SET_OBJECT; 136 137 err = nf_tables_bind_set(ctx, set, &priv->binding); 138 if (err < 0) 139 return err; 140 141 priv->set = set; 142 return 0; 143 } 144 145 static int nft_objref_map_dump(struct sk_buff *skb, const struct nft_expr *expr) 146 { 147 const struct nft_objref_map *priv = nft_expr_priv(expr); 148 149 if (nft_dump_register(skb, NFTA_OBJREF_SET_SREG, priv->sreg) || 150 nla_put_string(skb, NFTA_OBJREF_SET_NAME, priv->set->name)) 151 goto nla_put_failure; 152 153 return 0; 154 155 nla_put_failure: 156 return -1; 157 } 158 159 static void nft_objref_map_deactivate(const struct nft_ctx *ctx, 160 const struct nft_expr *expr, 161 enum nft_trans_phase phase) 162 { 163 struct nft_objref_map *priv = nft_expr_priv(expr); 164 165 nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase); 166 } 167 168 static void nft_objref_map_activate(const struct nft_ctx *ctx, 169 const struct nft_expr *expr) 170 { 171 struct nft_objref_map *priv = nft_expr_priv(expr); 172 173 priv->set->use++; 174 } 175 176 static void nft_objref_map_destroy(const struct nft_ctx *ctx, 177 const struct nft_expr *expr) 178 { 179 struct nft_objref_map *priv = nft_expr_priv(expr); 180 181 nf_tables_destroy_set(ctx, priv->set); 182 } 183 184 static struct nft_expr_type nft_objref_type; 185 static const struct nft_expr_ops nft_objref_map_ops = { 186 .type = &nft_objref_type, 187 .size = NFT_EXPR_SIZE(sizeof(struct nft_objref_map)), 188 .eval = nft_objref_map_eval, 189 .init = nft_objref_map_init, 190 .activate = nft_objref_map_activate, 191 .deactivate = nft_objref_map_deactivate, 192 .destroy = nft_objref_map_destroy, 193 .dump = nft_objref_map_dump, 194 }; 195 196 static const struct nft_expr_ops * 197 nft_objref_select_ops(const struct nft_ctx *ctx, 198 const struct nlattr * const tb[]) 199 { 200 if (tb[NFTA_OBJREF_SET_SREG] && 201 (tb[NFTA_OBJREF_SET_NAME] || 202 tb[NFTA_OBJREF_SET_ID])) 203 return &nft_objref_map_ops; 204 else if (tb[NFTA_OBJREF_IMM_NAME] && 205 tb[NFTA_OBJREF_IMM_TYPE]) 206 return &nft_objref_ops; 207 208 return ERR_PTR(-EOPNOTSUPP); 209 } 210 211 static const struct nla_policy nft_objref_policy[NFTA_OBJREF_MAX + 1] = { 212 [NFTA_OBJREF_IMM_NAME] = { .type = NLA_STRING, 213 .len = NFT_OBJ_MAXNAMELEN - 1 }, 214 [NFTA_OBJREF_IMM_TYPE] = { .type = NLA_U32 }, 215 [NFTA_OBJREF_SET_SREG] = { .type = NLA_U32 }, 216 [NFTA_OBJREF_SET_NAME] = { .type = NLA_STRING, 217 .len = NFT_SET_MAXNAMELEN - 1 }, 218 [NFTA_OBJREF_SET_ID] = { .type = NLA_U32 }, 219 }; 220 221 static struct nft_expr_type nft_objref_type __read_mostly = { 222 .name = "objref", 223 .select_ops = nft_objref_select_ops, 224 .policy = nft_objref_policy, 225 .maxattr = NFTA_OBJREF_MAX, 226 .owner = THIS_MODULE, 227 }; 228 229 static int __init nft_objref_module_init(void) 230 { 231 return nft_register_expr(&nft_objref_type); 232 } 233 234 static void __exit nft_objref_module_exit(void) 235 { 236 nft_unregister_expr(&nft_objref_type); 237 } 238 239 module_init(nft_objref_module_init); 240 module_exit(nft_objref_module_exit); 241 242 MODULE_LICENSE("GPL"); 243 MODULE_AUTHOR("Pablo Neira Ayuso <[email protected]>"); 244 MODULE_ALIAS_NFT_EXPR("objref"); 245